uclibc-ng/libutil/logwtmp.c

/* wtmp support rubbish (i.e. complete crap)

   Written by Erik Andersen <andersee@debian.org> 

   The GNU C Library is free software
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <string.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <utmp.h>
#include <fcntl.h>
#include <sys/file.h>


void logwtmp (const char *line, const char *name, const char *host)
{
    struct utmp lutmp;
    memset (&(lutmp), 0, sizeof (struct utmp));

    lutmp.ut_type = (name && *name)? USER_PROCESS : DEAD_PROCESS;
    lutmp.ut_pid = getpid();
    strncpy(lutmp.ut_line, line, sizeof(lutmp.ut_line)-1);
    strncpy(lutmp.ut_name, name, sizeof(lutmp.ut_name)-1);
    strncpy(lutmp.ut_host, host, sizeof(lutmp.ut_host)-1);
#if __WORDSIZE_COMPAT32 == 0
    gettimeofday(&(lutmp.ut_tv), NULL);
#else
    {
      struct timeval tv;
      gettimeofday (&tv, NULL);
      lutmp.ut_tv.tv_sec = tv.tv_sec;
      lutmp.ut_tv.tv_usec = tv.tv_usec;
    }
#endif

    updwtmp(_PATH_WTMP, &(lutmp));
}

#if 0
/* This is enabled in uClibc/libc/misc/utmp/wtent.c */
extern void updwtmp(const char *wtmp_file, const struct utmp *lutmp)
{
    int fd;

    fd = open(wtmp_file, O_APPEND | O_WRONLY, 0);
    if (fd >= 0) {
	if (lockf(fd, F_LOCK, 0)==0) {
	    write(fd, (const char *) lutmp, sizeof(struct utmp));
	    lockf(fd, F_ULOCK, 0);
	    close(fd);
	}
    }
}
#endif